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Full-Text Articles in Physical Sciences and Mathematics

Bowen Fluoresence And He Ii Lines In Active Galaxies And Gaseous Nebulae, Hagai Netzer, Moshe Elitzur, Gary J. Ferland Dec 1985

Bowen Fluoresence And He Ii Lines In Active Galaxies And Gaseous Nebulae, Hagai Netzer, Moshe Elitzur, Gary J. Ferland

Physics and Astronomy Faculty Publications

We have calculated the intensity of He II and the O III and N III Bowen lines under a variety of astrophysical conditions. Our line-transfer method is based on the escape probability formalism and is especially suitable for combining line fluorescence and photoionization calculations in a simple, straightforward way. It reproduces the results of the more sophisticated line-transfer calculations quite accurately and is much better for producing realistic ionization and thermal structures. An extensive grid of models is presented and discussed, with special emphasis on the case of active galactic nuclei (AGNs). Many O III and N III Bowen lines …


The Hydrogen Line Spectra Of Narrow-Line Radio Galaxies, Gary J. Ferland, Donald E. Osterbrock Feb 1985

The Hydrogen Line Spectra Of Narrow-Line Radio Galaxies, Gary J. Ferland, Donald E. Osterbrock

Physics and Astronomy Faculty Publications

We report the results of the first detection of Lyα in a narrow-line radio galaxy. Nearly simultaneous optical and UV observations of 3C 192 and 3C 223 allow the measurement of both Balmer and Lyman decrements. These line ratios are approximate functions of the interstellar reddening and of a parameter which is proportional to the amount of H I collisional excitation present. The reddening of 3C 192 is slightly larger than that due to our Galaxy, although 3C 223 may have a larger value. Both galaxies have intrinsic Balmer and Lyman decrements which are significantly steeper than case B, …